The Lockheed Martin Skunk Works sub-scale X-33 technology
demonstrator shown in this computerized concept drawing represents the
next generation Reusable Launch Vehicle. Incorporating proven technology,
the X-33 is designed to deliver commercial or military payloads to low
Earth orbit.

X-33

Space plane

ventures closer

By 1st Lt. Chris Hemrick

Air Force Flight Test Center

Public Affairs

Imagine
a future where a space plane lifts off from Edwards Air Force Base, Calif.,
and flies to Malmstrom Air Force Base, Mont. — about 950 miles — in about
20 minutes. Now, imagine that future is within two years.

Base organizations at the Air Force Flight Test Center
at Edwards have teamed up with Lockheed Martin Skunk Works to develop and
test the X-33, a 53 percent scale model of the future Reusable Launch Vehicle,
called Venture Star.

Through flight and ground demonstrations, the X-33 will
provide information necessary to allow the Lockheed Martin Corporation
to make a decision on whether to proceed in the development of the full-scale,
commercial, single-stage-to-orbit RLV. If created, the Venture Star would
eventually replace the space shuttle as the next generation space transportation
system.

"The goal is to lower costs from approximately $10,000
per pound down to around $1,000 per pound to get into orbit," said Chuck
Rogers, Air Force Flight Test Center X-33 launch integration engineer/manager
of the 412th Test Wing’s Access to Space Office.

Members of Team Edwards who are assisting the Skunk Works,
and the NASA Marshall Space Flight Center (the program head) with this
program include the AFFTC, Air Force Research Laboratory Propulsion Directorate
and NASA, Dryden Flight Research Center.

"It’s a real paradigm shift that the industry pays the
government for products, services and facilities, as a subcontractor to
the contractor," said Rogers. The team prepared and presented proposals
in competition with White Sands, N.M., and Kennedy Space Center, Fla.,
to be the X-33 launch site.

"Edwards was selected to be the X-33 launch site because
of the excellent launch corridor available for launches toward the northeast,
and our extensive flight test infrastructure and experience, which makes
this an ideal place to test experimental vehicles, said Rogers. "Between
Edwards and Utah, and Edwards and Montana are some of the most sparsely
populated areas in the United States. That’s very advantageous for launching
a vehicle like this, since we want the program to be as safe as possible."

Fifteen-flight program

The X-33 will blast off from the site near Haystack Butte,
located at the eastern edge of Edwards. A 15-flight program is planned
for the X-33 from the launch site now under construction. The X-33 team
already has defined the first seven flights that will, if successful, produce
the data needed to provide the confidence for a decision to proceed with
the full scale Venture Star.

Graphic courtesy Lockheed Martin

Construction began in November to prepare a 25-acre site
at Edwards Air Force Base, Calif., to become the sub-scale X-33 technology
demonstrator launch site.

Construction has already begun on the X-33 and major components
are already taking shape. The large tank that will contain the liquid oxygen
has been completed, and the final assembly jigs are already in place at
the Skunk Works facility at Palmdale.

An unmanned, autonomous vehicle, the X-33 uses differential
Global Positioning System with a radar altimeter for navigation and landing.

"The differential GPS will guide it through its flight
and down the runway for landing," said Rogers. "Some commands can be sent
up to the X-33 from the ground, but the X-33 will operate as an autonomous
vehicle during normal operations. The uplink to the X-33 would only be
used if the vehicle deviates significantly from its planned flight path."

Rogers said the X-33 preflight and flight operations will
be monitored and controlled from a refurbished operations control center
located at Haystack Butte. There also will be range safety officers at
the downrange sites.

Mach 15, 55 miles up

The X-33 is designed to travel at a top speed of Mach
15 (15 times the speed of sound), which is about three miles a second.
The prototype will not achieve orbit, which would require a speed of more
than Mach 25.

Once the X-33 is readied for flight, the engines will
be fired two times on the launch pad, with the second firing having a duration
of 20 seconds. The longest flight will be about 20 minutes at an altitude
of about 55 miles. The plan is to demonstrate a two-day turnaround for
the vehicle, said Rogers.

On Nov. 14, ground was broken for the launch site near
Haystack Butte. Maj. Gen. Richard L. Engel, Edwards Air Force Base commander,
predicted the X-33 would be a world-class vehicle researchers will use
to learn incredibly important lessons.

If the venture is a success, a permanent launch facility
could be built in the Edwards area. From here, vehicles could be launched
in nearly any direction except south, with some launches going to equatorial
orbits and some to polar orbits, returning to the central site (Edwards)
to be launched again. This would allow a fleet of RLVs to be based at one
site, according to Rogers.

The X-33 is expected to affirm new technology, such as
the linear aerospace engine, a large composite liquid hydrogen tank and
the spacecraft’s lifting body design.

The engines compensate for altitude and are believed to
be more efficient and a better fit for the wedged-shaped aircraft than
conventional bell nozzle rocket engines, according to NASA officials.

Landing sites include Michael Army Air Field at Dugway
Proving Ground in Utah, and at Malmstrom, near Great Falls, Mont. One of
NASA’s 747s will be used to carry the X-33 from its landing destinations
back to Edwards, said Rogers.

Projected rollout, flight in ‘99

The projected date for the X-33 rollout is May 1999, with
its first flight planned for that July. The program is scheduled to be
completed by 2000. Once the X-33 demonstrates the technology, the contractor
will solicit private investors for the RLV, Rogers said.

"If the X-33 program proves successful, there’s going
to be a competition for the RLV launch site. The Edwards area will definitely
be a competitor," said Rogers.

"The selection of Edwards for the X-33 launch site is
a win-win for both the program and Edwards, as well as the Antelope Valley,"
said Johnny Armstrong, acting chief of the AFFTC Access to Space Office.

"AFFTC participation in the X-33 program provides the
opportunity for our personnel to hone their skills toward support of space-related
programs that could provide valuable payoffs in the future, as the Air
Force transitions into a Space and Air Force."